Improve release note

Author: maxrjones

changes/3802.feature.md

@@ -1,3 +1,11 @@
-Add support for creating arrays with rectilinear (variable-sized) chunk grids by passing
-dask-style nested sequences to the ``chunk_shape`` parameter in ``zarr.create``. This feature
-is experimental and must be explicitly enabled via ``zarr.config.set({'array.rectilinear_chunks': True})``.
+Add support for rectilinear (variable-sized) chunk grids. This feature is experimental and
+must be explicitly enabled via ``zarr.config.set({'array.rectilinear_chunks': True})``.
+
+Rectilinear chunks can be used through:
+
+- **Creating arrays**: Pass nested sequences (e.g., ``[[10, 20, 30], [50, 50]]``) to ``chunks``
+  in ``zarr.create_array``, ``zarr.from_array``, ``zarr.zeros``, ``zarr.ones``, ``zarr.full``,
+  ``zarr.open``, and related functions, or to ``chunk_shape`` in ``zarr.create``.
+- **Opening existing arrays**: Arrays stored with the ``rectilinear`` chunk grid are read
+  transparently via ``zarr.open`` and ``zarr.open_array``.
+- **Rectilinear sharding**: Shard boundaries can be rectilinear while inner chunks remain regular.